New Unibody Macbook...2.0 vs. 2.4

Hi guys, I'm new here, and I just wanted your opinions on the new MacBooks. I'm a student looking to purchase one in the next 3 months, and I was wondering which I should get, my main uses would be word processing, and basic internet.
I was thinking 2.4 with 4GB RAM and keeping the HD as is until I can afford to upgrade...
Though, from what I've been reading, the 2.0 with 4GB and upgraded HD doesn't run bad either.
I'm not that computer savvy, however, I would like this laptop to last me through med school (I'll be starting in July), so that would be at least 7 years.

yeah but for 7 years? who knows how many cores/processing speed there might be by then. get the faster processor. 7 years from now (if your not obsessed with the next fastest new computer and have replaced it) you will be happier.

I figure, that through Apple, buying the 2.0 with upgraded RAM and HD would run me about $1,400 without taxes
Do you think I should buy stock, and get the RAM and HD elsewhere?

Edit: I'm a new Mac user, I've been reading about the Snow Leopard release, would I have to pay for that? or would it come as a free dl like ipod firmware?
I guess the question I'm asking is should I wait till the release?